Organic electroluminescent panel and producing method of the same

ABSTRACT

An organic electroluminescent element formed on a substrate has a layer structure in which organic layer including an organic electroluminescent layer is sandwiched between a pair of electrodes. A film formation region of an emission layer which is made of a uniform film forming material in accordance with one opening of a film forming mask is formed by plural layers including a first emission layer and a second emission layer. The layers are formed at each setting of the film forming mask.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to an organic electroluminescentpanel and a producing method thereof.

[0003] 2. Description of the Related Art

[0004] In an organic electroluminescent (Hereinafter, referred to “EL”)panel, a surface-emitting element due to luminescent areas of an organicEL element is formed on a substrate. A single or plural surface emittingelements are arranged to form a display region. A lower electrode havingone of various structures is formed on a substrate. A film pattern oforganic layers including an organic electroluminescent layer is thenformed, and an upper electrode is formed on the film pattern. When thefilm pattern is formed, a film forming mask which has openingscorresponding to the pattern shape is used, and a desired pattern isformed by a film forming method such as the mask vapor depositionmethod.

[0005] The pattern formation of the organic layers by using a filmforming mask will be described. Usually, luminescent areas of an organicEL element are defined by an insulating film formed on a substrate. Afilm pattern of organic layers is formed on the luminescent areas byusing a film forming mask having an opening which is slightly larger insize than the luminescent areas. In the case of plural-color display,film forming masks respectively having openings corresponding toelectroluminescent color patterns are used. The masks are adequatelyreplaced with one another or slid so that organic electroluminescentlayers of different colors are formed (See JP-A-2002-367787).

[0006] The organic layer refers to layer having an organicelectroluminescent layer constituting organic EL (such as an emissionlayer, a hole-transport layer, an electron-transport layer, ahole-injection layer, and an electron-injection layer) which include anorganic electroluminescent layer, and which are to be stacked above andbelow the organic electroluminescent layer. An organic EL element is notrestricted to have plural organic layers, and may consist of a singlelayer, or only an organic electroluminescent layer. For a hole-transportlayer and an electron-transport layer which are usually made of a singlematerial on the same substrate, film forming masks having differentpatterns for respective electroluminescent colors are often used inorder to control the film thickness in respective electroluminescentcolor regions (See JP-A-2001-237068).

[0007] In the case of a single-color display, a film forming mask havinga predetermined pattern (for example, a stripe shape) corresponding to aluminescent areas is used. In order to avoid the strength of the maskfrom being reduced by excessive density of openings, a film pattern oforganic layers is formed in a display region while the formation pitchof the openings is enlarged, and plural film formation steps areconducted (See JP-A-2000-48954).

[0008] The pattern formation using the film forming mask is oftenemployed not only in the above-described pattern formation of theorganic layers, but also in pattern formation of other components of anorganic EL element, such as upper and lower electrodes, an insulatingfilm, and a sealing film.

[0009] Hereinafter, a film formation region refers to a region whichforms each organic EL element in accordance with an opening of the filmforming mask. The film formation region set by a design of the openingsof the film forming mask. The film formation region is set by, forexample, the width or length of the opening or the position of theopening in the film forming mask.

[0010] In case where the film forming mask uses, when an organic ELpanel, the pattern formation of components such as organic layers,electrodes, an insulating film, and a sealing film uses a film formingmask are produced, a film forming material, dust, or the like(attachment substance a) sometimes adheres to an opening 1A of a filmforming mask 1. (Please see FIG. 1A) Alternatively, as shown in FIG. 1B,there is a partial design fault portion b with respect to the openingwidth 1h of the opening 1A. When the film forming mask 1 having defectsin the opening 1A uses for film formation, a film formation region hasan unformed portions c as shown in FIG. 1C. The unformed portions c isformed in accordance with the attachment substance and the design faultportion b, whereby the following problems are caused.

[0011] A thin-thickness portion is partially formed in the organiclayers interposed between upper and lower electrodes, thereby causingthe possibility that a leakage current flows between the upper and lowerelectrodes so that the emitted light cannot be obtained in a pixelhaving such a defective film formation region. When a pattern ofemission layer is formed, the unformed portion c of the film formationregion is formed so that the emission area of the emission layer isreduced and the brightness of the emission is lowered. Additionally,when a layer, which is adjacent to the emission layer, having anelectroluminescent is formed on the unformed regions of the filmformation region, the color of the emitted light, which is differentfrom predetermined one, is produced so that the chromaticity is changed.This will be described more specifically. When an electron-transportlayer made of Alq₃ or the like is formed in the unformed portion ofred-emitting layer, green emitted-light is produced therefrom, so thatthe predetermined chromaticity cannot be attained in the unitluminescent areas.

[0012] In pattern formation of the electrodes, the electric resistancepartially changes due to an unformed portion, so that a predeterminedinjection current cannot be obtained. In pattern formation of theinsulating film or the sealing film, there is the problem in that theinsulating or sealing performance is lowered by an unformed portion. Theinvention is proposed in order to solve these problems.

SUMMARY OF THE INVENTION

[0013] It is an object of the invention to provide an organicElectroluminescent (hereinafter, referred to “EL”) panel and a method ofproducing it in which, even when a defect such as an attachmentsubstance or a partial design fault exists in an opening of a filmforming mask, an unformed portion is not formed in a designed filmgrowth region, and functions of various portions corresponding to apreset film growth region can be exerted.

[0014] It is an another object of the invention such as that, In anorganic EL panel and a method of producing it, an unformed portion of afilm growth region related to a component of an organic EL element iseliminated to prevent a leakage current from flowing, that partialbrightness or chromaticity change is prevented from occurring, and thatexcellent insulating and sealing performances are ensured.

[0015] To achieve the above-objects, the invention has at least elementsregarding aspects of the invention as described below.

[0016] According to one aspect of the invention, there is provided withan organic electroluminescent panel in which an organicelectroluminescent element configured by sandwiching an organic layerincluding an organic electroluminescent layer between a pair ofelectrodes is formed on a substrate, wherein

[0017] one film formation region related to the organicelectroluminescent element which is made of a uniform film formingmaterial in accordance with one opening of the film forming mask isformed by plural layers which are formed respectively at each setting ofthe film forming mask.

[0018] According to another aspect of the invention, there is providedwith a producing method of an organic electroluminescent panel,including the steps of:

[0019] preparing an organic electroluminescent element including anorganic layer having an organic electroluminescent layer sandwichedbetween a pair of electrodes;

[0020] performing a setting of film formation mask; and

[0021] multiple-forming at each setting of the film formation mask onefilm formation region related to the organic electroluminescent andformed by a uniform film forming material in accordance with one openingof the film forming mask.

BRIEF DESCRIPTION OF THE DRAWINGS

[0022]FIG. 1 is a diagram illustrating problems of the related art;

[0023]FIGS. 2A and 2B are views showing film forming masks which is usedin a producing method of an organic electroluminescent panel accordingto the embodiments;

[0024]FIG. 3 is a diagram showing the structure of an organicelectroluminescent element in the organic electroluminescent panelaccording to the embodiments;

[0025]FIG. 4 is a diagram illustrating the organic EL panel and theproducing method thereof according to the embodiment, and showing theorganic EL panel in plan view;

[0026]FIGS. 5A and 5B are diagrams illustrating an embodiment (formationof emission layer);

[0027]FIG. 6 is a diagram illustrating an embodiment (formation ofemission layer);

[0028]FIGS. 7A and 7B are views showing a specific example of theembodiment; and

[0029]FIG. 8 is a section view illustrating an organic EL panel of anexample of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] Hereinafter, embodiments of the invention will be described withreference to the accompanying drawings. An organic electroluminescent(hereinafter, referred to “EL”) panel and a method of producing itaccording to an embodiment of the invention are based on the premisethat at least one of components of the organic EL element is formed bypattern formation using a film forming mask.

[0031]FIGS. 2A and 2B show example of a film forming mask used in theembodiment. In FIG. 2A, a film forming mask 1 has openings 1A which isformed in stripe shape. The openings 1A are arranged in parallel witheach other at predetermined intervals. The film forming mask may beused, for example, in case where emission layers of multi colors areformed in a pattern arrangement where unit luminescent areas of the samecolor are linearly arranged. In FIG. 2A, each of intervals between theopenings 1A allows to form two openings corresponding to the filmformation regions when the three colors is arranged. In FIG. 2B, a filmforming mask 1 has rectangular openings 1A which are arranged to bestaggered. The mask may be used in the case where emission layers ofmulti colors are formed in a pattern arrangement where unit luminescentareas of the same color are arranged to be staggered.

[0032] In the following description, the film forming mask 1 shown inFIG. 2A will be described as an example. However, embodiments of theinvention are not restricted to this. A film forming mask having thepattern shown in FIG. 2B may be similarly employed, and alternatively afilm forming mask having another mask pattern may be employed.

[0033] In the following description, film formation of an emission layerwill be described as an example. However, embodiments of the inventionare not restricted to this, and can be applied also to pattern formationof another component of an organic EL element.

[0034]FIG. 3 is a diagram showing the structure of an organic EL elementin an organic EL panel of the embodiment of the invention. The organicEL element 10 formed on a substrate 11 has a layer structure in whichorganic layers including an organic electroluminescent layer issandwiched between a pair of electrodes. More specifically, aninsulating film 13 is formed to surround a lower electrode 12 formed onthe substrate 11. A region which is above the lower electrode 12, andwhich is defined by the insulating film 13 is set as luminescent areas20 organic layers 30 are formed on the lower electrode 12 in theluminescent areas 20. An upper electrode 14 is formed on the organiclayers 30. In this example, the organic layers 30 have a three-layerstacked structure of a hole-transport layer 31, a emission layer 32, andan electron-transport layer 33. The stacked structure is notparticularly restricted to this. The upper electrode 14 may be coveredby a sealing film.

[0035] According to the embodiment of the invention, in the organic ELelement 10, one film formation region is formed by plural layers whichare formed respectively at different settings of the film forming mask.The one film formation region is related to one component of the organicEL element, and which is made of a uniform film forming material inaccordance with one opening of the film forming mask. In the exampleshown in FIG. 3, a film formation region S of the emission layer 32which is made of a uniform film forming material in accordance with oneopening of the film forming mask is formed by plural layers or a firstemission layer 32A and a second emission layer 32B. The layers 32A, 32Bare formed at settings of the film forming mask, respectively.

[0036] According to the example, even in the case where, in theformation of the first emission layer 32A, an attachment substance or apartial design fault exists in the opening of the film forming mask andan unformed portion c is formed, there is no possibility that anotherunformed portion c is overlappingly formed in the same place in thesubsequent film formation process. Therefore, the second emission layer32B which is to be subsequently formed is formed to cover the unformedportion c which has been formed, with result that it is possible to formthe single film formation region S in which no unformed portion c existsas a whole.

[0037]FIG. 4 is a diagram illustrating the organic EL panel and themethod of producing it according to the embodiment of the invention, andshowing the organic EL panel in plan view. When the film forming mask 1shown in FIG. 2A is used to form luminescent areas 20R, 20G, or 20B, afilm formation region S of the emission layer 32 formed in accordancewith the opening 1A is formed in stripe shape as shown in FIG. 4. eachof zones has the same color emitting light, and is linearly arranged.

[0038] In the method of producing the organic EL panel, when one filmformation region S related to the component of the organic EL element10, which is made of a uniform film forming material, formed inaccordance with one opening 1A of the film forming mask 1, filmformation is performed at each time when the setting of the film formingmask 1 is changed. Specifically, when the film formation region S of theemission layer 32 which is one of the components of the organic ELelement 10 is to be formed to a predetermined thickness by a uniformfilm forming material, the first emission layer 32A is first formed inaccordance with the opening 1A of the film forming mask 1. Then, thesetting of the film forming mask 1 is changed, and the second emissionlayer 32B is formed on the first emission layer 32A by the samematerial. Even when an unformed portion c is formed by a partial defectof the opening 1A during the forming process of the first emission layer32A, therefore, the second emission layer 32B in which another unformedportion c does not overlap with the unformed portion c is formed on thefirst emission layer as described above. As a result, the single filmformation region S in which no unformed portion c exists as a whole canbe formed. In the illustrated example, in order to form the red emittinglayer 20R, the film formation region S made of a material which emitsred luminescence is formed. As a red luminescent material, for example,a material in which Alq₃ is used as a host material and DCJTB (a productof Eastman Kodak Company) is used as a guest material can be employed.

[0039] As other embodiments, hereinafter, specific examples of changingof setting of the film forming mask will be described.

[0040] In a first example, setting of a film forming mask is changed bymoving an identical film forming mask by a distance which is equal to orsmaller than a design margin of an opening. The term “design margin ofan opening” means the width described below. Usually, a film formingmask is designed so that the size of each opening is slightly largerthan the film formation region. The film forming mask has a margin whichallows to be completely covered by a film forming material. In a statewhere the film forming mask is placed so that the center of the maskcoincides with that of the film formation region, a marginal width isset between an outer edge of the film formation region and that of theopening. The width refers to “design margin of an opening”. In thedescription, the movement of the film forming mask includes oscillationat an amplitude which is not larger than the design margin.

[0041] The embodiment will be described with reference to FIGS. 5A and5B with taking as an example the case where the above-described emissionlayer 32 is formed. The opening 1A of the film forming mask 1 is placedon the position indicated by the solid line. The first emission layer32A (not shown) is first formed on the luminescent areas 20. As shown inFIG. 5A, the film forming mask 1 is moved in the longitudinal directionof the stripe opening 1A by a distance L₁ which is equal to or smallerthan a design margin T₁ in the longitudinal direction of the opening 1A,and the second emission layer 32B (not shown) is then grown.Alternatively, as shown in FIG. 5B, the film forming mask 1 may be movedin the lateral direction of the stripe opening 1A by a distance L₂ whichis equal to or smaller than a design margin T₂ in the lateral directionof the opening 1A, and the second emission layer 32B (not shown) may bethen grown. Although the movements in the longitudinal and lateraldirections of the opening 1A are shown in this example, movement in anydirection may be conducted as far as the movement distance is equal toor smaller than a design margin.

[0042] Even when a defect 1A₁ or 1A₂ which will cause an unformedportion exists in the opening 1A and an unformed portion is formed inthe emission layer in the formation process of the first emission layer,therefore, the defect 1A₁ or 1A₂ which will cause an unformed portion ismoved by L₁ or L₂ in the process of growing the second emission layer.The emission layer is formed also on the unformed portion in theemission layer, with the result that a single film formation region inwhich no unformed portion exists as a whole is formed.

[0043] In a second example as shown in FIG. 5B, setting of a filmforming mask is changed by moving different openings of an identicalfilm forming mask having a pattern in which openings of the same shapeare placed at a predetermined pitch, onto a film formation region. Theembodiment will be described with reference to FIG. 6 with taking as anexample the case where the above-described emission layer 32 is formed.The film forming mask 1 has a pattern in which stripe openings 1A-1,1A-2, . . . are arranged at pitch p. The first emission layer is formedby using the film forming mask 1 which is placed in the illustratedstate. Then, the film forming mask 1 is moved by a distance which isequal to an integer multiple of the pitch p, so that, for example, theopening 1A-1 is placed on the film formation region which has been grownby using the opening 1A-2. Thereafter, the second emission layer isformed.

[0044] According to the configuration, even when a defect 1A₃ exists inthe openings 1A-1, a defect 1A₄ exists in the opening 1A-2, and thedefects respectively cause unformed portions to be formed in the processof growing the first emission layer, it is considered that the defectsof the openings do not exist in the same place, and hence the emissionlayer is grown in the process of growing the second emission layer, alsoon the unformed portion in the first emission layer. As a result, asingle film formation region in which no unformed portion exists as awhole is formed.

[0045]FIG. 7 shows a specific example of the embodiment. In thisexample, opening 1A-1 to 1A-4 the number of which is larger than that offilm formation region s that are to be patterned by the film formingmask 1 are formed in the film forming mask 1. After a first filmformation process, the film forming mask 1 is shifted by one pitch p,and a second film formation process is then conducted. In theillustrated example, emission layers are colored into three colors R, G,and B, and three places where a red emission layer is to be formed existon the substrate 11. By contrast, the four openings 1A-1 to 1A-4 areformed in the film forming mask 1. The film forming mask 1 is placed inthe state shown in FIG. 7A, and the first emission layer is then formed.As shown in FIG. 7B, the film forming mask 1 is moved by one pitch p. Onthe film formation region Si to S₄ where the first emission layer hasbeen formed, a second emission layer of the same material is thenformed.

[0046] In a third example, setting of a film forming mask is changed byreplacement to a different film forming mask having the same pattern.Referring again FIG. 6, the embodiment will be described with taking asan example the case where a emission layer is grown. First, a firstemission layer is formed by using the film forming mask 1 which isplaced in the illustrated state. Then, the film forming mask 1 isreplaced with another film forming mask having the same pattern, and asecond emission layer of the same material is grown.

[0047] According to the configuration, even when an unformed portion isformed in the film formation process of the first emission layer byusing the film forming mask 1, a defect does not exist in the sameplaces of the different film forming masks, and hence the emission layeris formed in the film formation process of the second emission layer,also on the unformed portion in the first emission layer. As a result, asingle film formation region in which no unformed portion exists as awhole is formed.

[0048] In the embodiments described above, the film formation of theemission layer 32 is conducted by the two processes of respectivelygrowing the two layers or the first emission layer 32A and the secondemission layer 32B. Alternatively, the emission layer may be dividedinto plural or three or more sublayers, and the emission layer may beformed by plural film formation processes.

[0049] When a film formation region where no unformed portion exists inthe process of growing an emission layer is formed as in theabove-described embodiments, the emission area can be prevented frombeing reduced, so that a preset brightness can be ensured. Furthermore,an EL layer which is adjacent to the emission layer is not formed in anunformed portion. Therefore, an electroluminescent color, which isdifferent from the preset one, does not occur, and the chromaticity isnot changed. As a result, even when dust or the like attaches to anopening of a film forming mask or a defect such as a partial designfault exists in the opening itself, excellent luminescence performancecan be ensured.

[0050] Although the embodiments have been described with focusing on thefilm formation of the emission layer, the invention is not limited tothem. The invention can be applied also to a pattern formation processusing a film forming mask, on components of an organic EL element, suchas another organic layer (irrespective of whether the layer is one whichis formed so as to correspond to the electroluminescent color, or onewhich is formed so as to be common to all colors), an electrode, aninsulating film, and a sealing film. In pattern formation of anelectrode, elimination of an unformed portion allows the electricresistance to be uniformalized, whereby driving can be stabilized in thewhole display screen. In pattern formation of an insulating film or asealing film, elimination of an unformed portion enables an excellentinsulating or sealing performance to be ensured.

[0051] Although the embodiments have been described with focusing on anorganic EL panel which is formed so as to emit multi colors, the organicEL panel of the invention is not restricted to such a panel, and may bea panel of monochromatic luminescence, or plural- or two or more-colorluminescence. In order to realize an organic EL panel of plural-colorluminescence, anyone of methods including the above-describedseparate-color region method can be employed as far as the method uses afilm forming mask to form a film formation region Examples of suchmethods are: a method (CF method or CCM method) in which a luminescentlayer of a mono-color such as white or blue is combined with a colorconverting layer based on a color filter or a fluorescent layer; amethod (photobleaching method) in which plural-color luminescence isrealized by, for example, irradiating a emission layer of a mono-colorluminescent layer with an electromagnetic wave; and a printing methodwhich uses a polymer material.

EXAMPLES

[0052] Hereinafter, specific examples of constituting members of anorganic EL panel in which the above-described embodiments can beemployed. A production steps will be described as examples of theinvention.

[0053]FIG. 8 is a sectional view schematically showing the structure ofan organic EL panel which is an example of the invention.

[0054] In the organic EL panel 2, the above-described organic EL element10 is formed on the substrate 11. As described above, the organic ELelement 10 has a structure in which the organic layers 30 are sandwichedbetween the pair of the lower electrode 12 and the upper electrode 14,and the insulating film 13 partitions the lower electrode 12 so as toform unit luminescent areas. A sealing member 40 which covers theorganic EL element 10 is bonded via an adhesive agent 41 onto thesubstrate 11. A desiccant 42 is attached to the inner face of thesealing member 40.

[0055] Hereinafter, each of the components will be described morespecifically.

[0056] a. Electrodes: Either of the lower electrode 12 and the upperelectrode 14 can be used as an anode or a cathode. The anode is made ofa material having a work function which is higher than that of thecathode, or configured by a film of a metal such as chromium (Cr),molybdenum (Mo), nickel (Ni), or platinum (Pt), or a transparentconductor film of, for example, a metal oxide film such as ITO or IZO.By contrast, the cathode material has a work function which is lowerthan that of the anode. The cathode material may be aluminum (Al) ormagnesium (Mg), an amorphous semiconductor such as doped polyaniline ordoped polyphenylene-vinylene, or an oxide such as Cr₂O₃, NiO, or Mn₂O₅.In the case where both the lower and upper electrodes are made of atransparent material, a configuration is employed in which a reflectionfilm is disposed on the side of the electrode opposite to the lightemission side.

[0057] b. Organic layers (organic electroluminescent layer): Usually,the organic material layers 30 are formed by a combination of thehole-transport layer 31, the emission layer 32, and theelectron-transport layer 33 as in the above-described embodiment (seeFIG. 3). Alternatively, plural emission layers 32, hole-transport layers31, and electron-transport layers 33 may be stacked in place of asingle-layer stack. One or both of the hole-transport layer 31 and theelectron-transport layer 33 may be omitted. Organic layers such as ahole-injection layer and an electron-injection layer may be inserted inaccordance with the usage of the panel. The materials of thehole-transport layer, the emission layer, and the electron-transportlayer can be suitably selected from conventionally known materials(including a fluorescent material, a phosphorous material, alow-molecular weight material, and a polymer material).

[0058] c. Adhesive agent: As the adhesive agent 41, useful are adhesiveagents such as those of the thermosetting type, the chemical-setting(two-component) type, and the photo (UV) setting type. As the materialof the adhesive agent, an acrylic resin, an epoxy resin, polyester,polyolefin, or the like can be used. The use of a UV curing epoxy resinis particularly preferable.

[0059] d. Desiccant: The desiccant 42 is formed by: a physical desiccantsuch as zeolite, silica gel, carbon, or carbon nanotubes; a chemicaldesiccant such as an alkali metal oxide, a metal halide, or chlorideperoxide; a desiccant in which an organic metal complex is dissolved ina petroleum solvent such as toluene, xylene, or an aliphatic organicsolvent; or a desiccant in which desiccant particles are dispersed in atransparent binder such as polyethylene, polyisoprene, or polyvinylcinnamate.

[0060] e. Sealing member (sealing film): The sealing member 40 can beconfigured by a member such as: that in which a sealing recess (such asa one-step depression, or a two-step depression including a depressionfor placement of the desiccant) is formed by a process such as pressmolding, etching, or blasting in a sealing substrate that can beselected from glass, plastic, or metal, and preferably made of glass; orthat in which plate glass is used, and which cooperates with asupporting substrate to form a sealing space by means of spacers made ofglass (or plastic). The sealing configuration is not limited to them,and the organic EL element 10 may be sealed by a sealing film. Thesealing film can be formed by a single-layer film or a stack of pluralprotective films. The sealing film may be made of either one of aninorganic material and an organic material. Examples of an inorganicmaterial are: nitrides such as SiN, AlN, and GaN; oxides such as SiO,Al₂O₃, Ta₂O₅, ZnO, and GeO; carbonitrides such as SiCN; metal fluorides;and metal films. Examples of an organic material are an epoxy resin, anacrylic resin, polyparaxylene, fluorinated polymers (perfluoroolefin,perfluoroether, tetrafluoroethylene, chrolotrifluoroethylene,dichrolodifluoroethylene, and the like), metal alkoxides (CH₃OM, C₂H₅OM,and the like), a polyimide precursor, and a perylene compound. Themanner of stacking, and the material are adequately selected inaccordance with the design of the organic EL element.

[0061] f. Production method: The organic EL element 10 is produced inthe following manner. First, the lower electrode 12 of ITO or the likefunctioning as an anode is formed in the form of a thin film on theglass substrate 11 by a method such as vapor deposition or sputtering,and then patterned to a desired shape by photolithography. Next, theorganic layers 30 are formed by: a wet process including a coatingmethod such as the spin coating method, or the dipping method, and aprinting method such as the screen printing method or the ink jetmethod; or a dry process such as the vapor deposition method or thelaser transfer method. For example, materials of a hole-transport layer,a emission layer, an electron-transport layer are sequentially stackedby the vapor deposition method.

[0062] At this time, the above-described film forming mask 1 is used inthe formation of the emission layer, so that separate color emissionlayers are formed in accordance with plural electroluminescent colors.In the formation of separate colors, an organic material which producesluminescences of three colors or RGB, or a combination of organicmaterials forms a emission layer in pixel regions corresponding to RGB.As in the embodiment described above, film growth using the samematerial is conducted two or more times on one luminescent areas,whereby an unformed portion is prevented from being produced in theluminescent areas.

[0063] Finally, the upper electrode 14 in the form of a metal thin filmis formed as a cathode configured by several stripes which areorthogonal to the lower electrode 12, so that a matrix structure isformed by the lower electrode 12 and the upper electrode 14. The thinfilm of the upper electrode 14 is formed by a method such as vapordeposition or sputtering.

[0064] A step of sealing the sealing member 40 and the substrate 11 viathe adhesive agent 41 is conducted in the following manner. An adequateamount (about 0.1 to 0.5 wt. %) of spacers (preferably, spacers made ofglass or plastic) having a diameter of 1 to 300 m is mixed with anadhesive agent of a UV curing epoxy resin. The mixture is applied byusing a dispenser or the like to a place of the substrate 11corresponding to the side wall of the sealing member 40. Under anatmosphere of an inert gas such as argon gas, thereafter, the sealingmember 40 butts against the substrate 11 via the adhesive agent 41. Theadhesive agent 41 is then irradiated with UV rays from the side of thesubstrate 11 (or from the side of the sealing substrate) to be cured. Inthis way, the organic EL element 10 is sealed in the state where thesealing space between the sealing member 40 and the substrate 11 isfilled with the inert gas such as argon gas.

[0065] A design change which is applied to the examples withoutdeparting from the configuration of the invention falls within the scopeof the invention. In place of the passive driving method, for example,the active driving method in which the panel is driven by TFTs may beemployed as the method of driving the organic EL panel. The lightemission from the organic EL element 10 may be of the bottom emissiontype in which light is emitted from the side of the substrate 11, or ofthe top emission type in which light is emitted in the oppositedirection.

[0066] According to the embodiments and experiments which are configuredas described above, even when a defect such as an attachment substanceor a partial design fault exists in an opening of a film forming mask,an unformed portion is not formed in a designed film formation region,and functions of various portions corresponding to a preset filmformation region can be exerted. Specifically, in an organic EL paneland a method of producing it, an unformed portion of a film formationregion is eliminated, so that a leakage current can be prevented fromflowing, partial brightness or chromaticity change can be prevented fromoccurring, and excellent insulating and sealing performances can beensured.

What is claimed is:
 1. An organic electroluminescent panel in which anorganic electroluminescent element configured by sandwiching an organiclayer including an organic electroluminescent layer between a pair ofelectrodes is formed on a substrate, wherein one film formation regionrelated to the organic electroluminescent element which is made of auniform film forming material in accordance with one opening of the filmforming mask is formed by plural layers which are formed respectively ateach setting of the film forming mask.
 2. The organic electroluminescentpanel according to claim 1, wherein the setting of the film forming maskis changed by moving an identical film forming mask by a distance whichis equal to smaller than a design margin of the opening.
 3. The organicelectroluminescent panel according to claim 1, wherein the setting ofthe film forming mask is changed by moving different opening of anidentical film forming mask onto the film formation region, and the filmforming mask having the opening formed by same shape is placed at apredetermined pitch.
 4. The organic electroluminescent panel accordingto claim 1, wherein the setting of the film forming mask is changed byreplacing the film forming mask with a different film forming maskhaving a same pattern of the opening.
 5. The organic electroluminescentpanel according to claim 1, wherein the organic electroluminescentelement is an emission layer of the organic layer.
 6. A producing methodof an organic electroluminescent panel, comprising the steps of:preparing an organic electroluminescent element including an organiclayer having an organic electroluminescent layer sandwiched between apair of electrodes; performing a setting of film formation mask; andmultiple-forming at each setting of the film formation mask one filmformation region related to the organic electroluminescent and formed bya uniform film forming material in accordance with one opening of thefilm forming mask.
 7. The producing method of an organicelectroluminescent panel according to claim 6, wherein the setting ofthe film forming mask is changed by moving an identical film formingmask by a distance which is equal to or smaller than a design margin ofthe opening of the film formation mask.
 8. The producing method of anorganic electroluminescent panel according to claim 6, wherein thesetting of the film formation mask is changed by moving differentopenings of an identical film forming mask onto the film formationregion, the film forming mask having the opening formed by same shape isplaced at a predetermined pitch.
 9. The producing method of an organicEL panel according to claim 6, wherein the setting of the film formingmask is changed by replacing the film forming mask with a different filmforming mask having a same pattern of the opening.
 10. The producingmethod of an organic electroluminescent panel according to claims 6,wherein the organic electroluminescent element is an emission layer ofthe organic layer.
 11. An organic electroluminescent panel comprising: asubstrate; a pair of electrodes positioned relative to the substrate;and an organic electroluminescent element including an organic layerhaving an organic electroluminescent layer disposed between the pair ofthe electrodes, wherein one film formation region is related to theorganic electroluminescent element which is made of a uniform filmforming material is formed in accordance with one opening of the filmforming mask, and the one film formation region is formed by plurallayers which are formed respectively at each setting of the film formingmask.
 12. The organic electroluminescent panel according to claim 11,wherein the setting of the film forming mask is changed by moving anidentical film forming mask by a distance which is equal to smaller thana design margin of the opening.
 13. The organic electroluminescent panelaccording to claim 11, wherein the setting of the film forming mask ischanged by moving different openings of an identical film forming maskonto the film formation region, and the film forming mask having theopening formed by same pattern is placed at a predetermined pitch. 14.The organic electroluminescent panel according to claim 11, wherein thesetting of the film forming mask is changed by replacing the filmforming mask with a different film forming mask having a same pattern ofthe opening.
 15. The organic electroluminescent panel according to claim11, wherein the organic electroluminescent element is an emission layerof the organic layer.